<?php
	$arr = array(
		array(
			"id"=>"1",
			"value"=>21
		),
		array(
			"id"=>"2",
			"value"=>22
		),
		array(
			"id"=>"4",
			"value"=>23
		)

	);

	$arr2 = array(

	);

	//方法一
	foreach ($arr as $key => $value) {  
		foreach ($arr2 as  $value2) {
			if($value['id'] == $value2['id']){
				$arr[$key] = $value + $value2;
			} 
		}
	}

	print_r($arr);
